200X from a 200S

[chopper]

Hi everyone - I'm new to the board and new to 4 strokes - I have a 200S (1984) and I would like to put the topend from a 200X - my question is: Do I just need the head and cam and carb to increase the comp. ratio to 9.6:1 from the 200S comp. ratio of 7.8:1 or do I need to replace the piston also - I was hoping I could use my stock sleeve and piston and just bolt the top end on. Thanx again and I"m sure I'll be getting lots of great info from this board - have a good one.
Dave

[200xer]

the piston and cam are different in the X and S motors. Everything else is the same. The piston is what adds the compression, but it is the same diameter. I would just buy a piston and ring set for a 200x (83-85) and get a used 200x cam from someone. It shouldn't be too expensive.

[chopper]

Thanx for the reply 200XER
Thats good news , I may as well go with the 12:1 piston while I'm changin the piston. So there is no difference in the carb? I assume I will have to do something to get more fuel in to accomadate the higher comp. What would you suggest?
Thanx
Again
Dave

[thefox]

If you are going to use a Wiesco 12:1 compression piston it needs 102 octane or better racing fuel. I put one in my 200s and it gets a lot of power but is a pain to find the gas for.